<template>
  <div>
    <!-- 面包屑导航区域 -->
    <el-breadcrumb separator-class="el-icon-arrow-right">
      <el-breadcrumb-item :to="{ path: '/home' }">首页</el-breadcrumb-item>
      <el-breadcrumb-item>商品管理</el-breadcrumb-item>
      <el-breadcrumb-item>分类参数</el-breadcrumb-item>
    </el-breadcrumb>

    <!-- 卡片区域 -->
    <el-card>
      <!-- 警告区域 -->
      <el-alert title="注意：只允许给第三级分类设置相关参数！"
                type="warning"
                show-icon
                :closable="false">
      </el-alert>

      <!-- 选择商品分类区域 -->
      <el-row class="cat_opt">
        <el-col>
          <span>选择商品分类：</span>
          <!-- 选择商品分类的级联选择框 -->
          <el-cascader v-model="selectedCateKeys"
                       :options="cateList"
                       :props="cascaderProps"
                       @change="handleChange"></el-cascader>
        </el-col>
      </el-row>

      <!-- tabs 页签区域 -->
      <el-tabs v-model="activeName"
               @tab-click="handleTabClick">
        <!-- 添加动态参数的面板 -->
        <el-tab-pane label="动态参数"
                     name="many">
          <!-- 添加参数的按钮 -->
          <el-button type="primary"
                     size="mini"
                     :disabled="isBtnDisabled"
                     @click="addDialogVisible = true">添加参数</el-button>
          <!-- 动态参数表格 -->
          <el-table :data="manyTableData"
                    border
                    stripe>
            <!-- 展开列 -->
            <el-table-column type="expand">
              <template slot-scope="scope">
                <!-- 循环渲染tag标签 -->
                <el-tag v-for="(item,i) in scope.row.attr_vals"
                        :key="i"
                        closable
                        @close="handleClosed(i,scope.row)">
                  {{item}}
                </el-tag>
                <!-- 输入的文本框 -->
                <el-input class="input-new-tag"
                          v-if="scope.row.inputVisible"
                          v-model="scope.row.inputValue"
                          ref="saveTagInput"
                          size="small"
                          @keyup.enter.native="handleInputConfirm(scope.row)"
                          @blur="handleInputConfirm(scope.row)">
                </el-input>
                <!-- 添加按钮 -->
                <el-button v-else
                           class="button-new-tag"
                           size="small"
                           @click="showInput(scope.row)">+ New Tag</el-button>
              </template>
            </el-table-column>
            <!-- 索引列 -->
            <el-table-column type="index"
                             label="#">
            </el-table-column>
            <el-table-column label="参数名称"
                             prop="attr_name">
            </el-table-column>
            <el-table-column label="操作">
              <template slot-scope="scope">
                <el-button type="primary"
                           icon="el-icon-edit"
                           size="mini"
                           @click="showEditDialog(scope.row.attr_id)">编辑</el-button>
                <el-button type="danger"
                           icon="el-icon-delete"
                           size="mini"
                           @click="removeById(scope.row.attr_id)">删除</el-button>
              </template>
            </el-table-column>
          </el-table>
        </el-tab-pane>
        <!-- 添加静态属性的面板 -->
        <el-tab-pane label="静态属性"
                     name="only">
          <!-- 添加属性的按钮 -->
          <el-button type="primary"
                     size="mini"
                     :disabled="isBtnDisabled"
                     @click="addDialogVisible = true">添加属性</el-button>
          <!-- 静态属性表格 -->
          <el-table :data="onlyTableData"
                    border
                    stripe>
            <!-- 展开列 -->
            <el-table-column type="expand">
              <template slot-scope="scope">
                <!-- 循环渲染tag标签 -->
                <el-tag v-for="(item,i) in scope.row.attr_vals"
                        :key="i"
                        closable
                        @close="handleClosed(i,scope.row)">
                  {{item}}
                </el-tag>
                <!-- 输入的文本框 -->
                <el-input class="input-new-tag"
                          v-if="scope.row.inputVisible"
                          v-model="scope.row.inputValue"
                          ref="saveTagInput"
                          size="small"
                          @keyup.enter.native="handleInputConfirm(scope.row)"
                          @blur="handleInputConfirm(scope.row)">
                </el-input>
                <!-- 添加按钮 -->
                <el-button v-else
                           class="button-new-tag"
                           size="small"
                           @click="showInput(scope.row)">+ New Tag</el-button>
              </template>
            </el-table-column>
            <!-- 索引列 -->
            <el-table-column type="index"
                             label="#">
            </el-table-column>
            <el-table-column label="属性名称"
                             prop="attr_name">
            </el-table-column>
            <el-table-column label="操作">
              <template slot-scope="scope">
                <el-button type="primary"
                           icon="el-icon-edit"
                           size="mini"
                           @click="showEditDialog(scope.row.attr_id)">编辑</el-button>
                <el-button type="danger"
                           icon="el-icon-delete"
                           size="mini"
                           @click="removeById(scope.row.attr_id)">删除</el-button>
              </template>
            </el-table-column>
          </el-table>

        </el-tab-pane>
      </el-tabs>
    </el-card>

    <!-- 添加动态参数/静态属性对话框 -->
    <el-dialog :title="'添加'+ titleText"
               :visible.sync="addDialogVisible"
               width="50%"
               @close="addDialogClosed">
      <el-form :model="addForm"
               :rules="formRules"
               ref="addFormRef"
               label-width="100px">
        <el-form-item :label="titleText"
                      prop="attr_name">
          <el-input v-model="addForm.attr_name"></el-input>
        </el-form-item>
      </el-form>
      <span slot="footer"
            class="dialog-footer">
        <el-button @click="addDialogVisible = false">取 消</el-button>
        <el-button type="primary"
                   @click="addParams">确 定</el-button>
      </span>
    </el-dialog>

    <!-- 编辑动态参数/静态属性对话框 -->
    <el-dialog :title="'编辑'+ titleText"
               :visible.sync="editDialogVisible"
               width="50%"
               @close="editDialogClosed">
      <el-form :model="editForm"
               :rules="formRules"
               ref="editFormRef"
               label-width="100px">
        <el-form-item :label="titleText"
                      prop="attr_name">
          <el-input v-model="editForm.attr_name"></el-input>
        </el-form-item>
      </el-form>
      <span slot="footer"
            class="dialog-footer">
        <el-button @click="editDialogVisible = false">取 消</el-button>
        <el-button type="primary"
                   @click="editParams">确 定</el-button>
      </span>
    </el-dialog>
  </div>
</template>

<script>
export default {
  data() {
    return {
      // 商品分类数据列表
      cateList: [],
      // 级联选择框的配置对象
      cascaderProps: {
        expandTrigger: 'hover', value: 'cat_id',
        label: 'cat_name',
        children: 'children'
      },
      // 级联选择框双向绑定到的数组
      selectedCateKeys: [],
      // 被激活的页签的 名称
      activeName: 'many',
      // 动态参数的数据
      manyTableData: [],
      // 静态属性的数据
      onlyTableData: [],

      // 控制添加对话框的显示与隐藏
      addDialogVisible: false,
      // 添加的表单数据
      addForm: {
        // 参数名称
        attr_name: ''
      },
      // 控制编辑对话框的显示与隐藏
      editDialogVisible: false,
      // 修改表单的数据对象
      editForm: {},
      // 表单的验证规则
      formRules: {
        attr_name: [
          { required: true, message: '请输入参数名称', trigger: 'blur' }
        ]
      },

    }
  },
  created() {
    this.getCateList()
  },
  methods: {
    async getCateList() {
      const { data: res } = await this.$http.get('categories')
      if (res.meta.status != 200) {
        this.$message.error('获取商品分类数据失败！')
      }

      this.cateList = res.data
      // console.log(this.cateList)
    },
    // 级联选择框选中项变化，会触发这个函数
    handleChange() {
      this.getParamsData()
    },
    // tab 被选中时触发
    handleTabClick() {
      console.log(this.activeName)
      this.getParamsData()
    },
    // 获取参数的列表数据
    async getParamsData() {
      // 判断 selectedCateKeys的length ≠ 3，证明选中的不是三级分类
      if (this.selectedCateKeys.length !== 3) {
        this.selectedCateKeys = []
        this.manyTableData = []
        this.onlyTableData = []
        return
      }
      // 选中的是三级分类
      console.log(this.selectedCateKeys)
      // 根据所选分类的Id，和当前所处的面板，获取对应的参数
      const { data: res } = await this.$http.get(`categories/${this.cateId}/attributes`, {
        params: { sel: this.activeName }
      })
      if (res.meta.status != 200) {
        return this.$message.error('获取参数列表失败！')
      }

      res.data.forEach(item => {
        item.attr_vals = item.attr_vals ? item.attr_vals.split(' ') : []
        // 控制按钮与文本框的切换显示
        item.inputVisible = false
        // 文本框中输入的内容
        item.inputValue = ''
      });
      console.log(res.data)

      if (this.activeName === 'many') {
        this.manyTableData = res.data
      } else {
        this.onlyTableData = res.data
      }
    },
    // 监听 添加对话框的关闭事件
    addDialogClosed() {
      this.$refs.addFormRef.resetFields()
    },
    // 点击确认，添加参数
    addParams() {
      this.$refs.addFormRef.validate(async valid => {
        if (!valid) return

        const { data: res } = await this.$http.post(`categories/${this.cateId}/attributes`, {
          attr_name: this.addForm.attr_name,
          attr_sel: this.activeName
        })
        if (res.meta.status != 201) {
          return this.$message.error('添加参数失败！')
        }
        // 重新获取参数的列表数据
        this.getParamsData()
        // 关闭添加对话框
        this.addDialogVisible = false
      })
    },
    // 根据Id 删除指定的参数
    async removeById(attrid) {
      const confirmResult = await this.$confirm('此操作将永久删除该参数, 是否继续?', '提示', {
        confirmButtonText: '确定',
        cancelButtonText: '取消',
        type: 'warning'
      }).catch(err => err)

      // 用户取消了删除操作
      if (confirmResult != 'confirm') {
        return this.$message.info('取消了删除！')
      }

      const { data: res } = await this.$http.delete(`categories/${this.cateId}/attributes/` + attrid)
      if (res.meta.status != 200) {
        return this.$message.error('删除参数失败！')
      }

      // 重新获取参数的列表数据
      this.getParamsData()
      this.$message.success('删除参数成功！')
    },
    // 编辑参数
    async showEditDialog(attrid) {
      // 显示编辑对话框
      this.editDialogVisible = true

      // 根据Id查询分类参数的数据
      const { data: res } = await this.$http.get(`categories/${this.cateId}/attributes/` + attrid, {
        attr_sel: this.activeName
      })
      if (res.meta.status != 200) {
        return this.$message.error('查询数据失败！')
      }
      this.editForm = res.data
    },
    // 监听 编辑对话框的关闭处理事件
    editDialogClosed() {
      this.$refs.editFormRef.resetFields()
    },
    // 编辑对话框
    editParams() {
      this.$refs.editFormRef.validate(async valid => {
        if (!valid) return

        // 发起更新参数信息的网络请求
        const { data: res } = await this.$http.put(`categories/${this.cateId}/attributes/` + this.editForm.attr_id, {
          attr_name: this.editForm.attr_name,
          attr_sel: this.activeName
        })
        if (res.meta.status != 200) {
          return this.$message.error('更新失败！')
        }
        this.$message.success('更新成功！')
        // 重新获取参数的列表数据
        this.getParamsData()
        this.editDialogVisible = false
      })
    },
    // 文本框失去焦点 或 按下 Enter键 都会触发
    async handleInputConfirm(row) {
      if (row.inputValue.trim().length === 0) {
        row.inputValue = ''
        // 隐藏文本框，显示按钮
        row.inputVisible = false
        return
      }

      // 如果没有return ，则证明输入的内容，需要后续处理
      row.attr_vals.push(row.inputValue.trim())
      row.inputValue = ''
      row.inputVisible = false

      // 需要发起请求，保存这次操作
      this.saveAttrValus(row)
    },
    // 将对 attr_vals 的操作保存到数据库
    async saveAttrValus(row) {
      const { data: res } = await this.$http.put(`categories/${this.cateId}/attributes/${row.attr_id}`, {
        attr_name: row.attr_name,
        attr_sel: row.attr_sel,
        attr_vals: row.attr_vals.join(' ')
      })

      if (res.meta.status != 200) {
        return this.$message.error('修改参数项失败！')
      }
      this.$message.success('修改参数项成功！')
    },
    // 点击添加按钮，显示输入文本框
    showInput(row) {
      // 显示文本框
      row.inputVisible = true
      // 让文本框自动获取焦点
      // $nextTick 方法的作用：就是当页面上的元素被重新渲染之后，才会执行回调函数之后的代码
      this.$nextTick(_ => {
        this.$refs.saveTagInput.$refs.input.focus();
      });
    },
    // 删除对应的参数可选项
    handleClosed(i, row) {
      row.attr_vals.splice(i, 1)
      // 发起请求，保存本次操作
      this.saveAttrValus(row)
    }
  },
  // 计算方法
  computed: {
    // 如果按钮需要禁用，则返回true，否找返回false
    isBtnDisabled() {
      if (this.selectedCateKeys.length !== 3) {
        return true
      }
      return false
    },
    // 选中的三级分类的Id
    cateId() {
      if (this.selectedCateKeys.length === 3) {
        return this.selectedCateKeys[2]
      }
      return null
    },
    // 动态计算标题的文本 
    titleText() {
      if (this.activeName === 'many') {
        return '动态参数'
      }
      return '静态属性'
    }
  }
};
</script>

<style lang='less' scoped>
.cat_opt {
  margin: 15px 0;
}
.el-tag {
  margin: 5px;
}
.input-new-tag {
  width: 130px;
}
</style>
